Panel assembly with noise attenuation system

Abstract

A panel assembly includes a first panel defining a surface, and a boom attenuation panel. The boom attenuation panel includes a circumferential edge, and a central portion. The boom attenuation panel is attached to the surface of the first panel, along the circumferential edge of the boom attenuation panel. The central portion of the boom attenuation panel is spaced from the surface of the first panel a gap distance to form a gas chamber between the surface of the first panel and the central portion of the boom attenuation panel. The gas chamber contains a gas that is moveable within the gas chamber in response to wave-like motion of the first panel. Movement of the gas increases the effective acoustic mass of the boom attenuation panel, and damped the wave-like motion of the first panel, which operates to reduce noise generated from the wave-like motion of the first panel.

The invention claimed is: 
     
       1. A panel assembly comprising:
 a first panel defining a surface; 
 a boom attenuation panel having a circumferential edge and a central portion; 
 wherein the boom attenuation panel is attached to the surface of the first panel along the circumferential edge of the boom attenuation panel; 
 wherein the central portion of the boom attenuation panel is disposed in a generally parallel relationship with the surface of the first panel, and is spaced from the surface of the first panel by a gap distance to form a gas chamber between the surface of the first panel and the central portion of the boom attenuation panel in order to reduce noise generated from a wave-like motion of the first panel; and 
 wherein the gas chamber contains a gas that is moveable within the gas chamber in response to wave-like motion of the first panel; 
 wherein the boom attenuation panel is continuously attached to the first panel, around the entire circumferential edge of the boom attenuation panel, to completely seal the gas chamber and prevent the escape of the gas from the gas chamber between the circumferential edge of the boom attenuation panel and the surface of the first panel; 
 wherein the boom attenuation panel includes and is manufactured from a fiber reinforced cardboard material. 
 
     
     
       2. The panel assembly set forth in  claim 1  wherein the gap distance is between the range of 1.5 mm and 5.0 mm. 
     
     
       3. The panel assembly set forth in  claim 1  further comprising a trim panel disposed adjacent the boom attenuation panel, with the boom attenuation panel disposed between the trim panel and the first panel. 
     
     
       4. The panel assembly set forth in  claim 3  wherein the trim panel is spaced from the boom attenuation panel by a separation distance. 
     
     
       5. The panel assembly set forth in  claim 4  wherein the separation distance is equal to or greater than 1.0 mm. 
     
     
       6. The panel assembly set forth in  claim 1  wherein the first panel is an exterior body panel of a vehicle. 
     
     
       7. The panel assembly set forth in  claim 1  wherein the first panel includes and is manufactured from a metal material. 
     
     
       8. The panel assembly set forth in  claim 1  wherein the boom attenuation panel is bonded to the first panel with an adhesive. 
     
     
       9. A vehicle comprising:
 a body having a roof panel defining an exterior body surface and an interior surface; 
 a boom attenuation panel having a circumferential edge and a central portion; 
 a trim panel disposed adjacent the boom attenuation panel, with the boom attenuation panel disposed between the trim panel and the roof panel; 
 wherein the boom attenuation panel is attached to the interior surface of the roof panel along the circumferential edge of the boom attenuation panel; 
 wherein the central portion of the boom attenuation panel is disposed in a generally parallel relationship with the surface of the roof panel, and is spaced from the interior surface of the roof panel by a gap distance to form a gas chamber between the interior surface of the roof panel and the central portion of the boom attenuation panel; 
 wherein the gas chamber contains a gas that is moveable within the gas chamber in response to wave-like motion of the roof panel, to increase the effective acoustic mass of the boom attenuation panel and dampen the wave-like motion of the roof panel, to reduce noise generated from the wave-like motion of the roof panel; and 
 wherein the boom attenuation panel is continuously attached to the roof panel, around the entire circumferential edge of the boom attenuation panel, to completely seal the gas chamber and prevent the escape of the gas contained in the gas chamber between the circumferential edge of the boom attenuation panel and the interior surface of the roof panel. 
 
     
     
       10. The vehicle set forth in  claim 9  wherein the gap distance is between the range of 1.5 mm and 5.0 mm. 
     
     
       11. The vehicle set forth in  claim 10  wherein the trim panel is spaced from the boom attenuation panel by a separation distance that is equal to or greater than 1.0 mm.